I saw the blinkt! Light online and like the idea of playing with the LED bar. I was wondering if it would be possible to program the lights to change color depending on the system i am playing in retropie/emulation station? I was thinking something like

NES=Red SNES=White Sega=Blue

Would serve no real purpose besides looking cool. I know its possible, just not sure where to start. Any tips?

You can figure out which emulator is running and what command-line was used to start it using the ps command on Linux. Python should be able to call this command and determine which emulator is running by, for example, the ROM file path.

I don’t have a running RetroPie system to hand right now to get more specific, but the best place to start is by enabling SSH on your Pi, connecting while a ROM is running and then seeing what you get by running ps aux